Improving the efficiency of a converter for charging a low voltage battery and a converter for charging a high voltage battery, which is directly connected to improving the fuel efficiency, is an essential task as interests in an environmentally-friendly car have risen due to environmental pollution that becomes a global issue.
In a plug-in hybrid car and an electric car, the efficiency of a charger and an LDC (low voltage DC-DC converter) is directly related to the fuel efficiency. According to a conventional method, an input and output voltage range is wide and thus a current at a primary side becomes large, and the charger and the LDC are manufactured as different products, thereby decreasing the efficiency and increasing a size.
Further, the reduced efficiency increases heat of the charger and the converter, thereby causing a radiant heat problem.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept and therefore it may contain information that does not form the prior art.